Assessment of Explanatory Variables on the Failure Rate of Circuit Breakers Using the Proportional Hazard Model

This paper utilises the proportional hazard model to understand and quantify the impact of explanatory variables on the failure rate of circuit breakers (CB). Particularly, 4496 work orders with 2622 high voltage CBs are investigated with an occurrence of 281 major failures. Different explanatory variables such as CB type, manufacturer, preventive maintenance (PM), and others are gathered to quantify their significance and magnitude of their effect. The results present that PM has a positive impact, the number of operations within the last year a negative impact, and age has a small but negative impact on the failure rate. The CB type is not significant in all analyses which can he explained by examining the PM and age of these CB types. This paper contributes to the understanding of how explanatory variables impact the failure rate which is essential for power system asset management.